Release v1.8.12

Docker reference: paritytech/substrate-relay:v1.8.12

Bundled Chain Versions:

Rococo: 1_016_001;
Westend: 1_016_001;
Kusama: 1_004_001;
Polkadot: 1_004_001;
Rococo Bridge Hub: 1_016_001;
Westend Bridge Hub: 1_016_001;
Kusama Bridge Hub: 1_009_001;
Polkadot Bridge Hub: 2_000_003;
Rococo Bulletin: not supported yet;
Polkadot Bulletin: not supported yet.

What's Changed

• Bump quote from 1.0.41 to 1.0.42 by @dependabot[bot] in #3193
• upgrading Polkadot BH runtime to v2.0.3 release by @rosarp in #3194

Full Changelog: v1.8.11...v1.8.12